Tank building form



June 16, 1959 H. NOYES ET AL 2,890,489

TANK BUILDING FORM Filed March 21, 1952 4 Sheets-Sheet 1 INVENTOR. H OWAR D NOYE S EDWARD W. MOORMAN TT'Y.

June 16, 1959 H. NOYES EIAL 2,890,489

TANK BUILDING FORM Filed March 21, 1952 4 Sheets-Sheet 2 INVENTOR.HOWARD NOYES 20 55 2i EDWARD W.MO0RMAN June 16, 1959 H Es ETAL 2,890,489

TANK BUILDING FORM- 4 Sheets-Sheet 3 Fil ed March. 21 1952 ATT'Y.

H. NOYES ET AL TANK BUILDING FORM June 16, 1959 4 Sheets-Sheet 4 FiledMarch 21, 1952 INVENTOR.

HOWARD NOYES Y EDWARD W. MOORMAN fiwe ATT'Y.

United States PatentO T BUILDING FORM Howard Noyes and Edward W.Moor-man, Dayton, Ohio,

assignors to The Dayton Rubber Company, a corporation of OhioApplication March 21, 1952, Serial No. 277,804

3 Claims. (Cl. 18-45) The present invention relates to building jigs foruse in making fuel tanks of the type extensively used in aircraft andmore particularly relates to building jigs, a portion of which isadapted for repeated use.

The flexible types of fuel tank or fuel cell, to which the presentinvention is directed, were made heretofore by building up the tank,layer by layer, over a rigid form having the shape it is desired toimpart to the interior of the tank being constructed. The form washeretofore made of pasteboard, cardboard or other material which iseasily disintegrated, so that it can be removed from the inside of thetank when the work of forming the tank has been completed.

After the tank form has been provided, it is covered with a number oflayers or laminations of rubber and fabric with intermediate layers ofrubber or other cement. When a sufiicient number of such layers havebeen applied to build up the wall of the tank to the desired thicknessand structure, the various tank fittings have been incorporated and thetank vulcanized. The form is then destroyed by softening it in hot waterand removing the disintegrated parts through a manhole or other openingin the tank.

The present invention contemplates an improved fuel tank building formwherein parts of the form are recoverable for repeated use therebygreatly reducing the cost of the expendable forms heretofore in use.

This is accomplished by providing the building jig in the form of aframework comprising two end members or brackets, a number of centersupports, and a number of elongated reinforcing and supporting members,which are shown for purposes of illustration as four lengths ofcardboard tubing, the pieces of tubing being attached to the endbrackets and supported by the center supports. To this framework,cardboard panels are attached by means of glue to complete the buildingform. Wood molding blocks with one side having the same contour as thecardboard tubes are glued to the tubes to provide a suitable surface forattaching the cardboard side panels. The cardboard tubes, in addition toproviding lateral strength, are of a size necessary to give the properradius for the edges of the tank.

The end brackets and center supports are made of a permanent materialand can be recovered for re-use, while the cardboard tubes and sidepanels are expended with each tank used. In order to facilitate removalfrom the tank after building and curing, the end brackets and centersupports are made in two parts that are latched together duringassembly, and can be disassembled by reaching an arm through a regularopening in the cured tank, releasing each latch, and removing each ofthe pieces, one at a time, through the same opening. Preformed shapes ofcardboard, plastic or papier mach may be used for reinforcement and theforming of various radii at the corners. While the elongated reinforcingmembers have been illustrated in the form of paper tubes, elongatedmembers of other shapes or curvature may be Patented June- 16, 1959used, for example, instead of tubes, curved cardboard strips may be usedwhich will be engaged by the end members in any desired manner. In placeof paper or other disintegratable material, the elongated membersmay bemade of re-usable material, such as cotton, plastic, metal, or the like,formed in interlocking sections so that these members can be taken apartand removed through the opening in the finished tank.

By employing the method and form of the present invention, not only isthere a saving in the cost of the forms used, but there is also a savingin the cost of labor involved. Furthermore, the building jig of thepresent invention is of more rigid construction than forms heretoforeused.

The above and other features and advantages of the present inventionwill be apparent from the following. detailed description taken inconnection with the accompanying drawings, wherein:

Figure 1 is a perspective view of the fully assembled fuel tank buildingform forming the subject matter of the present invention.

Figure 2 is a similar view of the form with the cardboard panelsremoved.

Figure 3 is a transverse sectional view through the tank building jigshowing one form of center support, taken along line 3--3 of Figure 2.

Figure 4 is a similar view of a modified form of center support.

Figure 5 is an elevational view of the center support shown in Figure 3.

Figure 6 is a similar view of the center support shown in Figure 4.

Figure 7 is an elevational view of one form of end member assembly.

Figure 8 is a side view thereof.

Figure 9 is an elevational view of a modified form of an end memberassembly; and

Figure 10 is a side view thereof.

Referring to the drawings in detail, and more particularly to Figures 1and 2, the fuel tank (not shown) is built up about a form composedgenerally of a pair of end members 11, 12', a plurality of centersupports 13, 14, 15 and 16, and four cardboard tubes 17, 18, 19 and 20.The form is completed by attaching cardboard panels, indicated generallyby numeral 21, to the frame in a manner to be described.

In one form of the invention shown specifically in Figures 1, 2, 3, 7and 8, the center supports and endassemblies are formed of metal,preferably aluminum, while in the other modification shown specificallyin Figures 4, 6, 9 and 10, the center supports and end assemblies areformed of wood, preferably waterproof or marine plywood.

As seen in Figure 3, the center support 13 comprises two complementarysections 22 and 23 each forming one half of the center support. Thesection 22 comprises a vertical angle strip 24 suitably joined to anupper horizontal angle strip 25 by means of a corner bracket 26. Thelower portion of the section 22 combines the horizontal angle and cornerbracket indicated by numeral 27. The section 23 includes similar parts28, 29 and 30. As seen in Figure 5, the brackets 26, 27, 29 and 30 arecurved at 31 to conform to the longitudinal tubes 17, 18, 19 and 20.

The sections 22 and 23 are constructed to form a rigid:

bracket members 27 and 30 are similarly provided with i a tongue 35, agroove 36 and a latch 37.

The center supports 14, 15 and 16 are similarly constructed. v

The end assembly 12, shown in Figures 7 and 8, is also formed of metal,preferably aluminum, and consists of the vertical members 38, 39 havinghorizontal sections 40 and 41 forming the upper edge and lowerhorizontal sections 42 and 43 forming the lower edge of the endassembly. The various portions making up the assembly are suitablyshaped to define the curved interior edges of the tank being formed. Themembers thus described are hollow and sector-shaped in cross section.Angle members 44 and 45 are secured to the vertical members 38 and 39for added strength and to provide a bearing surface for the cardboardside panels and end panels. Additional angle members 46 and 47 aresecured to the horizontal sections 40, 41, 42 and 43. The horizontalsections are formed with a tongue and groove construction similar to theconstruction previously described in connection with the center supportsand similar latches 48 and 49 are provided for securing the assembly inlocked position. The latch mechanisms in the end assemblies are fastenedat a 45 angle to facilitate disassembly. At each corner of the endassembly, spool members 50, 51, 52 and 53 are secured to the assemblyand are of suchsize as to receive the ends of the tubes 17, 18, 19 and20. The opposite end assembly 11 is similarly constructed.

In order to provide a suitable surface for attaching the panels 21, aplurality of Wood blocks are glued to the tubes 17, 18, 19 and 20. Theseblocks, indicated by numeral 54, are suitably shaped to provide theglueing surface with the same contour as the cardboard tubes. The blocksare suitably spaced along the tubes to receive the center supports inthe space between adjacent blocks thus serving as a means for properlylocating the supports. T

From the foregoing description, the manner of assembling the completedbuilding form will be readily apparent. The wood molding blocks 54 areadhered to the four cardboard tubes with a water soluble adhesive andthe ends of the tubes are mounted on the spools of the end assemblies 11and 12. The center supports are positioned in the spaces betweenadjacent blocks and the cardboard panels are glued to the blocks with awater, soluble adhesive. To provide a smooth exterior surface for theform, paper tape, indicated by numeral 55, is secured over the variousjoints. After the joints have been taped, and the tank fittings securedto the panels, the rubber compound forming the tank proper is applied tothe form in a well-known manner and cured. If desired, the cavitybetween the edge of the panels and the cardboard tubes or otherelongated member, which cavity is shown as 70 in Figures 3 and 4, may befilled with a strip of rubber extruded in the shape of the cavity beforeapplication of the paper tape. This strip can then be curved when theform is dismantled and removed from the tank.

After the curing step, the assembly is soaked in Water causingdisintegration of the cardboard panels and tubes. The end assemblies andcenter supports are disassembled by a workman reaching an arm through anopening, as at 10, Figure 1, in the cured tank and releasing each latch.The parts are then removed, one at a time through the same opening.Thus, it will be apparent that the cardboard panels and tubes areexpended with each tank built and the metal parts available for reuse inanother The center supports and end assemblies described above are madeof metal such as aluminum. In a modified form as shown in Figures 4, 6,9 and 10, the center supports are formed of wood, preferably of plywood.As seen in Figure 6, the center support, indicated by numeral 56,comprises a pair of complementary sections 57 and 58 pivotally joinedtogether by hinges 59 and 60. The sections are suitably cut away at eachof the outside corners to form curved portions cooperating with thetubes 17, 18, 19 and 20.

The modified end supports, shown in Figures 9 and 10, are formed of twocomplementary sections 61 and 62 hinged together by hinges 63 and 64. Asseen in Figure 10, the outer edge of each support is rounded ofi to folma smooth curved surface. A handle 65 is attached to an inner face of oneof the sections to aid in the disassembly of the support. At each cornerof the assembled support, wooden discs 66, 67, 68 and 69 are provided toreceive the ends of the cardboard tubes as previously described inconnection with members 50, 51, 52 and 53.

It will be understood that the modified center supports and modified endassemblies shown in Figures 4, 6, 9 and 10 are interchangeable with thecenter supports and end assemblies shown in the first form. The panels,tubes and wood molds previously described can be used with either formof center support or end assembly. In the assembly or disassembly of themodified construction the mode of operation is the same as previouslydescribed except that the parts are folded together to be removedthrough the tank opening as distinguished from the first form whereinthe complementary sections are completely separable.

It will be understood that various changes in details of constructioncan be made without departing from the spirit of the invention, thescope of which is commensurate with the appended claims.

We claim:

1. A form for the manufacture of hollow rubber articles and the like,which comprises a pair of spaced end assemblies, a plurality of spacedelongated members of water disintegratable material which engage acorner of each end assembly, thereby forming a frame and defining thecorners of the form, at least one interior member positionedintermediate the ends of said frame engaging and bracing said elongatedmembers, said end assemblies and said interior member being of waterresistant material but sectionally collapsible, and a plurality of waterdisintegratable wall panels secured to said frame and engaging thecorners thereof whereby the curvature of the corners is defined by thecurvature of the spaced elongated members.

2. A form for the manufacture of hollow rubber articles according toclaim 1 wherein said wall panels are secured to the frame by means ofspacing blocks mounted upon said water disintegratable elongated membersand providing a planar seating surface coextensive with said reinforcingmembers to receive said wall panels.

3. A form for the manufacture of hollow rubber articles according toclaim 2 wherein said spacing blocks are separated to provide spacingmeans for holding said interior members in fixed transverse position atdeterminate points along the length of said water disintegratableelongated members.

References Cited in the file of this patent UNITED STATES PATENTS

